It has it's own special day on the calendar, and it starred in a self-titled movie. Even so, there's a lot more to the groundhog than its mythical ability to predict the duration of winter.

The groundhog (Marmota monax), or woodchuck, is usually 1 to 2 1/2 feet long and weighs between seven and 14 pounds. Its short legs, stocky body and bushy tail are covered with thick brown fur, which can have a reddish or yellowish cast. It has a distinctive flat head, and its face can show small areas of pale white.

With an average life span of four to five years, the woodchuck is very active on sunny days and can be seen feeding on grasses, clover and alfalfa all over southern Canada and the eastern United States. In Oklahoma, you are most likely to see one in the extreme northeastern corner, within a few hundred feet of its burrow.
A prolific digger, the groundhog can create a new burrow overnight. Burrows are recognizable from the large mound of dirt that surrounds the main entrance. To keep its home from flooding, the woodchuck usually digs at an angle about five feet deep, then tunnels back up about two feet before excavating the actual burrow. From there, it usually digs a 30-foot tunnel, with one or two escape tunnels and two side chambers. One chamber is used entirely for waste disposal. Once filled, the animal will seal the chamber and build another. It uses the second chamber for sleeping, hibernation and nesting.

After the first heavy frost, a groundhog retires to its burrow and seals the entrance to its hibernation chamber. While hibernating, a woodchuck lives off its fat reserve. Its heart rate may drop from 100 beats per minute to just four beats a minute, and its body temperature may drop as much as 50 degrees. Length of hibernation varies by latitude, but most groundhogs leave their chambers in late February or early March. In Oklahoma, it's possible for groundhogs to emerge by Groundhog Day.

Upon leaving their burrows, male groundhogs are driven by an intense desire to mate. A male immediately searches for other groundhog burrows, and if it finds one containing only female scent, it will cautiously enter in hopes of acceptance.

As soon as courtship ends and the male departs, the female begins nesting by removing old grass from the hibernation chamber and bringing in new dry grass. Four to five kits will arrive about four weeks later. They are about an inch long and hairless when born, but they grow quickly on the high fat content of the mother's milk and double their weight within a week. By mid-summer, the young woodchucks leave their mother's burrow and occupy vacant burrows nearby. They remain under the mother's supervision until they leave the area in late summer.

Upon establishing their own territories, young woodchucks quickly burrow in time for hibernation the following winter. On Feb. 2, people across the nation watch closely for their emergence in hopes of an early spring.